Question

Which is equivalent to (9 y squared minus 4 x)(9 y squared + 4 x), and what type of special product is it?

Answer 1

B

Explanation:

Answer 2

`(9y^2-4x)\,(9y^2+4x)=81y^4-16x^2`

and it is the special factor product that leads to a difference of squares

Explanation:

The product:
`(9y^2-4x)\,(9y^2+4x)`

is a product of the form:

`(a-b)\,(a+b) = a^2-b^2`

which leads as shown to a difference of squares. So they binomials
`(a-b)` and
`(a+b)` are the factors of the difference of squares
`a^2-b^2`.

In our case, the product:

`(9y^2-4x)\,(9y^2+4x)= (9y^2)^2-(4x)^2=81y^4-16x^2`